1. Field of the Invention
The present invention relates to a patient interface assembly for being connected to a patient's respiratory system in order to provide a flow of gas to an airway of the patient and, in particular, to a patient interface assembly that includes cheek mount supports, which use the cheekbone to properly locate and fix the patient interface assembly on the face of the user.
2. Description of the Related Art
There are numerous situations where it is necessary or desirable to deliver a flow of breathing gas non-invasively to the airway of a patient, i.e., without intubating the patient or surgically inserting a tracheal tube in the esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation. It is also known to deliver continuous positive airway pressure (CPAP) or variable airway pressure, such as a bi-level pressure that varies with the patient's respiratory cycle or an auto-titrating pressure that varies with the monitored condition of the patient, to the airway of a patient/user. Typical pressure support therapies are provided to treat a medical disorder, such as sleep apnea syndrome, in particular, obstructive sleep apnea (OSA) or congestive heart failure and/or other medical and respiratory disorders, such as Cheynes-Stokes respiration, congestive heart failure, and stroke.
Non-invasive ventilation and pressure support therapies involve the placement of a patient interface assembly, which is typically a nasal or nasal/oral mask, on the face of a patient to interface the ventilator or pressure support system with the airway of the patient so that a flow of breathing gas can be delivered from the pressure/flow generating patient interface assembly to the airway of the patient. It is known to maintain such masks on the face of a patient by a headgear having upper and lower straps, each having opposite ends threaded through connecting elements provided on the opposite sides and top of a mask.
Because such masks are typically worn for an extended period of time, a variety of concerns must be taken into consideration. For example, in providing a pressure support therapy to treat OSA, the patient normally wears the patient interface patient interface assembly all night long while he or she sleeps. Patient interface development has generally involved balancing of two competing goals: a) secure attachment to and seal with the user's face to create an airtight seal in order to facilitate the required positive airway pressure, and b) comfort to the user in order to maximize patient compliance, i.e., usage of the medical therapy. An airtight seal can be achieved by tightening the mask down firmly against the patient's face. However, this solution often results in discomfort to the user due to relatively high strapping forces needed to ensure a secure seal against the patient and less than satisfactory patient compliance. Alternatively, the mask may be fit loosely on the patient's face to enhance comfort. However, the effectiveness of the mask may be compromised if it is too loose.
PCT application no. PCT/IB2011/050609 (PCT publication no. WO 2011/110961)(“the '961 application”), the contents of which are incorporated herein by reference, describes a patient interface assembly is described that includes a support member comprising a central support portion and a pair of cheek mount supports coupled to the central portion. Each cheek mount support is configured to apply a force a side a user's cheekbone while applying substantially no force over an apex of such a user's cheekbone responsive to the patient interface assembly being worn by a user. A seal member is coupled to the support portion. The seal member is adapted to seal against a surface of a user to communicate a flow of gas with an airway of such a user. A conduit coupling member is coupled to the seal member. The seal member comprises two conical nasal prongs, adapted for being inserted in the nasal passages of the patient.
The stability and fixation of the seal member and nasal prongs is obtained by the central support which is connected with cheek mount supports which are in contact with the face of the patient in the area around the cheekbone.
It is believed that the stability of the seal member and, if present, nasal prongs can further be improved. There exists a need for such a further improvement in industry.